Okay. This is odd. I load my save it, was Sunday. I looked in the locker room, found no. I was going to go through the week and look for her on Saturday, but before I got to the end of the week, I found Olivia in the locker room on Tuesday night.
You're right... It was actually Saturday or Tuesday... I just remembered incorrectly, and seems like the hint in the journal is a bit misleading in that case. Glad you found her eventually!